This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A338749 #4 Nov 08 2020 08:41:49
%S A338749 1,0,2,3,4,5,10,7,14,15,18,11,39,13,34,37,42,17,73,19,81,65,58,23,121,
%T A338749 45,104,87,115,29,212,31,158,109,118,113,240,37,184,182,235,41,366,43,
%U A338749 279,283,162,47,399,119,407,211,337,53,478,189,453,314,288,59,639
%N A338749 a(0) = 1; for n > 0, a(n) = n * Sum_{d|n, d < n} a(d - 1) / d.
%F A338749 G.f. A(x) satisfies: A(x) = 1 + 2 * x^2 * A(x^2) + 3 * x^3 * A(x^3) + 4 * x^4 * A(x^4) + ...
%t A338749 a[0] = 1; a[n_] := a[n] = n DivisorSum[n, a[# - 1]/# &, # < n &]; Table[a[n], {n, 0, 60}]
%t A338749 nmax = 60; A[_] = 0; Do[A[x_] = 1 + Sum[k x^k A[x^k], {k, 2, nmax}] + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
%Y A338749 Cf. A038046, A050369, A167865.
%K A338749 nonn
%O A338749 0,3
%A A338749 _Ilya Gutkovskiy_, Nov 06 2020